SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '379dc47352d4677bc24f83f6c981127b664033a0f20b550df457783c4848fbbf' 
  AND token = 'RCQ83dtjYxZQzdJns9n38s1ZLB2G+oTIKWb1huINZIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}